1 4 D O C S . 1 5 , 1 6 M A R C H 1 9 1 9 between them: 1 – 2 has the same value as when applying the nebula’s radial ve- locity now, that is: The agreement is remarkably good, although one should not draw conclusions from 2 stars.[4] Even if this method with the cal- cium lines probably still cannot be carried out immediately with the accuracy of the Orion nebula analysis, there is nevertheless some chance here of obtaining in the coming years ample information about the material distributed throughout the whole sky, especially since we are dealing here with a question that is also of purely general interest astronomically, since the puzzling behavior of the calcium lines is quite a brain twister. With best regards, yours, E. Freundlich. 15. To Erwin Freundlich [Berlin, 29 March 1919] Dear Freundlich, Your new result is highly gratifying.[1] I for my part am now convinced of the existence of the redshift. Special treatment of the individual lines would still be very desirable. You have done a great service to the cause with these two papers. I shall point this out emphatically to Mr. Nernst, in case it should be necessary.[2] If you now clear up the matter with the Sun as well,[3] confirmation of the theory’s most important result is then secured.– I told Mr. Scheel that you and Mr. Kohlschütter want to give talks at the G[er- man] Ph[ysical] Soc[iety]. Your talks are supposed to take place very soon al- ready.[4] I ask you both kindly to contact him by telephone. With best regards, yours, A. Einstein. 16. To Aurel Stodola Berlin, 31 March [1919][1] Esteemed Colleague,[2] At the sight of your friendly letter, my bad conscience, which had been plaguing me earlier already because I did not visit you again in Zurich, was hugely * nebula * calcium line δ Orionis +2.3 +2.0 ε Orionis 7.6 +8.9